Job Roles

100 cm is read as 102 cm

a = 100 x 100 sq.cm and b = 102 x 102 sq.cm

then, Increase in area = [ (102 x 102) - (100 x 100) ] sq.cm

percentage error =404100*100*100= 4.04%

Take a square of side 4cm and a rectangle having l=6cm and b=2cm

then perimeter of square = perimeter of rectangle

area of square = 16 sq.cm

area of rectangle = 12 sq.cm

Hence a >b

speed of the man = 4 x (5/18) m/sec = 10/9 m/sec

time taken = 3 x 60 sec = 180 sec

length of diagonal = speed x  time = (10/9) x 180 = 200m

Area of the field = (1/2) x (dioagonal)²

= (1/2) x 200 x 200 sq.m = 20000sq.m

let the side of the square be x meters
length of two sides = 2x meters
diagonal = 2x= 1.414x m

saving on 2x meters = .59x m

saving % = 0.59x2x*100%

= 30% (approx)

perimeter = total cost / cost per m = 10080 /20 = 504m
side of the square = 504/4 = 126m
breadth of the pavement = 3m
side of inner square = 126 - 6 = 120m
area of the pavement = (126 x126) - (120 x 120) = 246 x 6 sq m
cost of pavement = 246*6*50 = Rs. 73800

area of cross roads = (55 x 4) + (35 x 4)- (4 x 4) = 344sq m

cost of graveling = 344 x  (75/100) = Rs. 258

length of the diagonal = 52 x (15/60) =13m 

sum of length and breadth = 68 x (15/60) = 17m

l2+b2=13 or l+b =17

area =lb = 1/2[(2lb)] = 1/2[(l+b)² - (l²+b²)] = 1/2[17² -169]

=1/2 x 120 = 60 sq.m